Motion picture apparatus



Sept. 24, 1940. E. s. DORGELO E'l" AL 7 3 MOTION PI GTURE APPARATUS Filed Jan. 4, 1939 2 Sheets-Sheet l fijeclxl'ue 55 as Q 1/ 5G fVVE/VTO/F 007 9620 PM 0% (172 267; 2W

Sept. 24, 1940.

E. G. DORGELO ET AL MOTION PICTURE APPARATUS Filed Jan. 4, 1959 2 SheetsSheet 2 fina s 740,3

Patented Sept. 24,- 1940 "UNITED STATES PATENT OFECE -MOTI N morons APPARATUS Eduard Gerardus Dorgeio and Pieter Martinus van Alphen, Eindhoven, Netherlands, assignors, by mesne assignments, to Hartford National Bank and Trust Company, Hartford, 00mm, as

trustee Application January 4, 1939, Serial No. 249,834 In Germany January 8, 1938 6 Claims.

l0 compensation and also the shutter when used,.

with the result that perfect synchronlsm is always obtained between the movement of the pictures and of the mirror, and when a shutter is provided, also between the movement of the pic- 7 18' tures and the time during which the shutter is open. In addition to the above-mentioned synchronous motor, such an apparatus comprises a separate driving motor which drives the film.

' The above type 'of apparatus is particularly so suitable for projecting or recording with films of regenerated cellulose because such films are insufficiently rigid mechanically to permit their being carried forward by means of sprocket wheels and perforation holes.

86 We have found that when starting such an apparatus the frequency of the alternating current set up by the control marks gradually increases with the increasing film speed, and that at low frequencies, i. e. during starting, the am- 80 plifier, which supplies voltage to the synchronous motor, has only a very small output and is therefore incapable of supplying suflicient power to start this motor. On the other hand, "when the speed of the film has reached approximately its normal value, the frequency is of too high a. value to cause the synchronous motor to fall into step. As a result the synchronous motor frequently fails to start.

The object of the present invention is to overcome the above diiliculties, and for this purpose wqprovide additional driving means which may be coupled with the above-mentioned synchronous motor,-at least when the apparatus is being started.

As such auxiliary driving means we. may use a separate driving motor of high starting torque, for example a commutator motor. and perma nently couple this motor with the synchronous motor. However, to avoid the useof an additional motor we prefer to couple the synchronous motor with the film-driving motor either only during the starting or permanently. This coupling must be a slipping one as the speed of the synchronous motor depends upon the speed of the film and the ratio between the latter and (in. saas the speed of the driving motor may be slightly different from that of said coupling.

In order that the invention may he clearly understood and readily carried into effect, we shall describe the same in more detail with reference to the accompanyingdrawings, in which:

Figure l is a diagrammatic View of a portion of a reproducing apparatus embodying the invention, I

Fig. 2 is a partiy-sectionized view along line m d-t oi Figure i,

Fig. 3 is a plan view of the film of l and 2,

and V Fig. dis a diagrammatic view of a reproducing apparatus according to a second embodiment of the invention.

Fig. 5 shows diagrammatically a third embodi ment of the invention.

The apparatus shown in Figures 1. 2 and 3 comprises a curved film guide it provided with a 2 picture aperture 20 and a small control aperture 26 (see Fig. 2). A picture film it providedalong one edge with opaque control marks 2i (See Fig.

3) is driven over the curved surface of guide it? by a driving motor l6 of any suitable constant-. speed type. For this purpose film i0 is pressed by a pressing roller it upon the smooth driving surface of a roller i I. Fixedly connected to roller ii is a pulley l4 driven by a belt it from a pulley 50 mounted on the shaft of motor so At one side of the film guide i2 is a suitable light source 11 ands condenser lens it. The light passing through picture aperture 20 is reilected by a compensating mirror 2! through an objective at to thereby produce a stationary pic- 35 ture upon a screen (not shown). Mirror 2| is fixedly mounted upon a lever 22 adapted to be oscillated about an axis 52 perpendicular to the plane of the drawings. For this purpose lever 23 has a finger riding upon the edge of a cam 23 40 which is driven through bevel gears SI and 53 from a shaft 24 by a synchronous motor 2E5.

Fixedly mounted on shaft 24 is a shutter it. As

beam will be directed upon a prism 28 and than upon a photo-electric cell 29. These light impulses are transformed into substantially sinus- 55 oidal current variations, which after being anipllfied in an amplifier iii, are supplied to the synchronous motor 25 (see Fig. l). I

As has been stated above, at low frequencies, i. c. When the film iii is traveling at a low smed, the output of amplifier til is insufiicient to start motor 25. To overcome this dificulty we couple a separate motor to shaft Motor whic of is variable speed type, for instance a conunutator motor, and is connected to the ne voltage on y (not shown) as motor 66, miles ener for d "lying sh whereas serves only to maintain the shaft nchronouss speed. secrete motor oifl'iellt such -s sriown in T In figure, which is sim has ais, the gear n ovidecl vn' cove for a belt which pass so rotatabiy mounted on eccenrotated about a fir is connected to eccentric in the direction of the arrow thereby place e surface of pulley M. the shaft can driven from lid when the film has attained its l speed, lever can be returned to the norm whereby the motor will conas use a permanent coupling between the lving motor is and the shaft as shown In this figure, which is similar to i and has the same parts indicated by the eerence numerals, the coupling shaft 321 is provided between the film driving motor l6 and the shaft 2% of the synchronous motor 25. A bevel gear 38 is mounted on the shaft of motor H and meshes with a bevel gear 39 secured to a shaft d3 connected to shaft 37 through a coupling so (later to be referred to). A bevel gear 4! secured to the end of shaft 37 engages a bevel gear 42 fixedly mounted on the shaft 24.

As the motor it drives the film l0 and the synchronous motor and thus the shaft 24 is in perfect synchronism with the film, the coupling 40, shafts 31 and 43 form a second interconnection between the motors l6 and 25. When the ratio of transmission of the bevel gears 4|, 42 and 3B, 39 is not in perfect agreement with the ratio of the speeds of the motor 16 and the film III, the motor 25 will be thrown out of synchronism. In such a case perfect working of the reproducing apparatus would be impossible. To overcome this the ratio of transmission between the motor l6 and the shaft 24 is made variable by means of the slipping'coupling 40 between the shafts 31 and 43. The gears 39 and 38 are dimensioned in such a way that the shaft 43 will slightly overrun the shaft 37 at normal speed of the shaft 24. Although the motor l8 supports the rotation of the synchronous motor some difference in speed is allowed.

While we have described our invention with reference to specific examples and applications, we do not wish to be limited thereto but desire the appended claims to be construed as broadly as is permissible in view of the prior art.

What we claim is:

1. In a motion picture apparatus using nonmeans separate from said driving motor for moving said mirror in synchronism with the movement of the control. marks, said latter means including a rotary synchronous motor, and a. fixed coupling between said latter motor and said optical compensati n means, and means to supply additional power to said synchronous motor during the starting of the apparatus.

2. in a motion picture apparatus using nonperforated film provided with optical control ma means for continuously driving the dim past a picture gate including a driving motor, optical compen ation means including a mirror,

means separate horn sail "rivlng motor for noving said mirror er ichronism with the move ment of the control "narlzs, said latter means ineluding rotary synchronous motor, and a fixed coupling between. latter motor and said optical compensation and a motor coupled to said synchronous motor to supply additional power thereto during the starting of the apparatus.

3. In a motion picture using nonperforated films provided with optical control marks, means for continuously driving the film past a picture gate including a driving motor, optical compensation means including a mirror, means separate from said driving motor for moving said mirror in synchronism with the movement of the control marks, said latter means including a rotary synchronous motor, and a fixed coupling between said latter motor and said optical compensation means, and means to supply additional power to said synchronous motor during the starting of the apparatus, said last means including said driving motor.

4. In a motion picture apparatus using nonperforated films provided with optical control marks, means for continuously driving the film including a driving motor, optical compensation means including a mirror, a shutter, means for moving said mirror and shutter in synchronism with the movement of the control marks including a synchronous motor, and means to supply additional driving power to said mirror during the starting of the apparatus.

5. In a. motion picture apparatus using nonperforated films provided with optical control marks, means for continuously driving the film including a driving motor, a compensating mirror, means for moving said mirror in synchronism with the movement of the control marks including a shaft and a synchronous motor connected to said shaft, a shutter mounted on said shaft, and means to connect said shaft to said driving motor during the starting of the apparatus.

6. In a motion picture apparatus using nonperforated films provided with optical control marks, means for continuously driving the film including a driving motor, optical compensating means including a mirror, means for moving said mirror in synchronism with the movement of the control marks including asynchronous motor and a. shaft coupled thereto, means for coupling said driving motor permanently to said synchronous motor lncluding a slipping coupling.

EDUARD GERARDUS'DORGELO. PIE'I'ER MARTINUS VAR ALPHEN. 

